The present invention generally relates to a process and an apparatus for twisting cable elements and, in particular, relates to one such process and apparatus wherein the cable elements are drawn from fixed storage points, and during the twisting in the discharge direction are twisted in alternating directions and at the same time the twisted discharge is taken up in a storage path.
As used herein, the phrase "cable elements", as well as the idiomatic variations thereof, is taken to include, for example, the conductors of electrical and optical cables or lines of all kinds. In addition, the phrase "cable elements" can also include extended elements of a higher order, for example, where individual cable elements are already joined and are themselves to be reverse-twisted. These are, for example, pairs, quads or bundles. Further, the phrase "cable elements" can also include plastic threads or bare metal wires, or the like, which are used, for example, for the concentric protective conductor of high voltage power lines.
The so-called reverse-twisting, wherein the twist direction of the cable elements changes at intervals, has been used for a long time in the cable technology. Compared to twisting processes wherein the twist direction remains the same, the use of reverse-twisting is advantageous in that no rotating coils with the inherent large moving masses thereof are used. Conventionally, processes for twisting wherein the twist direction remains the same typically only provide a limited length for the twisted product to be manufactured. Furthermore, the use of reverse-twisting permits continuous manufacture at high discharge speeds.
In conventional reverse-twisting processes, for example, as discussed in DE-OS 22 62 705 it is known to guide the cable elements between a fixed and a rotating guide disk inside of hoses. The hoses are made of plastic with a low coefficient of friction, and are provided to prevent the individual cable elements from becoming tangled between the stationary disk and the rotating disk during the manufacturing run.
It has been found that such processes exhibit a number of drawbacks. For example, before such a twisting run can be started, each individual cable element must be threaded into the relatively long hoses. This step can be quite time consuming and therefore can be quite expensive. Furthermore, the hoses can be easily contaminated, or loaded up, to the point that the coefficient of friction between the hose and the cable element can lead to the breakage of the cable elements. Still further, the output capacity of conventional arrangements is limited by the number of twisted cables that can be stored.
Consequently, it is highly desirable to provide a process and a apparatus for the reverse-twisting of cable elements that does not require extensive threading time and overcomes the above-recited drawbacks of conventional processes and apparatus.